Here is the full list of all 14 Pizza Possum achievements.
Unlock every item in the game
Rob Bella of her delicious pizza three times
Find all Zeppole on the island
Chase an NPC halfway across the island
Visit every region on the island
Earn two crowns
Collect 30,000 points worth of food
Collect a crown from Bella
Eat Bella Chonki's gigantic pizza
Stun three guards at once
Unlock the smoke bomb
Have 4 guards chasing you at the same time
Gobble up the caprese salad
Unlock your first item